Positron emission tomography (PET) systems generate images that represent a distribution of positron-emitting nuclides within a body of a patient. When a positron interacts with an electron by annihilation, the entire mass of a positron-electron pair is converted into two photons. The photons are emitted in opposite directions along a line of response (LOR). The annihilation photons are detected by detectors that are placed on both sides of the line of response, in a configuration such as a detector array or detector ring. The detectors convert the incident photons into useful electrical signals that can be used for image formation. An image thus generated based on the acquired image data includes the annihilation photon detection information. Often, such PET systems may be integrated together with a computed tomography (CT) system to form a dual-modality imaging system (PET/CT imaging system).
The detectors included by PET or PET/CT systems are often arrays of photodiodes, such as silicon photomultipliers (SiPMs), that detect light impulses from an array of scintillation crystals. The detectors are often mounted in close proximity to readout electronics to preserve a signal integrity of the photodiodes. In operation, the readout electronics generate heat that may affect the operation of the photodiodes. Accordingly, it is desirable to provide cooling for the detectors.